This paper introduces a new signal detection method for Low cost, Low power and Low complexity (L3) TR-UWB systems for medium to low data rate applications such as sensors networks. This new detection method is based on a time_to_space conversion realizable by an analog waveform sampler. This method overcomes the major difficulties in a traditional TR-UWB detection methods based on wide band delay lines. Finally the relaxed timing precision needed in symbol synchronization contributes further to lower the system power consumption. This concept has been validated by simulation with real data from experimental setup. The results will be presented and compared also with other solutions.